There has been a demand for extended wear life of pneumatic tires. On the other hand, a demand for weight reduction of tires is also strong due to reasons such as reducing an environmental load, reducing manufacturing costs, and improving riding comfort. Generally, the wear life is extended by using a method of increasing a design width of a tread section, a method of decreasing the groove area of the tread section, and a method of increasing the thickness of the tread section thereby increasing the groove depth (for example, see Patent Document 1). Nevertheless, these methods entail increase in the tire weight. For this reason, it is difficult to achieve both the extension of the wear life and the reduction of the tire weight at the same time.
Furthermore, there is recently a strong demand for improving wet braking performance at a running speed exceeding 100 km/h to cope with the increasing speed of vehicles. If the groove area ratio in the tread section is increased in view of such a demand, the wear life is further reduced.